Pyridine → Pyrrolo[2,1-f][1,2,4]triazine-2,4(1H,3H)-dione

HRID 2117284Notes

Reaction equation

HRID 2117284 reaction equation
Cl[C:2](OCC)=[O:3].[NH2:7][N:8]1[CH:12]=[CH:11][CH:10]=[C:9]1[C:13]([NH2:15])=[O:14].N1C=CC=CC=1>O1CCOCC1>[NH:7]1[C:2](=[O:3])[NH:15][C:13](=[O:14])[C:9]2=[CH:10][CH:11]=[CH:12][N:8]12

Participants

5

Reactant 3

HCID 1049PyridineHCID 10928Ethyl chloroformateHCID 104191801-Amino-1H-pyrrole-2-carboxamide

Product 1

HCID 15604988Pyrrolo[2,1-f][1,2,4]triazine-2,4(1H,3H)-dioneYield 63%

Reagents, catalysts & solvents 1

HCID 312751,4-DioxaneSolvent

Conditions

Temperature
155 °C

Procedure

Ethyl chloroformate (4.9 ml, 51 mmol) was added dropwise to a stirred mixture of 1-amino-1H-pyrrole-2-carboxamide (5.85 gm, 46.7 mmol, Journal of Heterocyclic Chemistry, 1994, 31, 781) and dry pyridine (4.2 mL, 51 mmol) in dry dioxane (48 mL) under N2 at RT. The mixture was heated at reflux for 1 hr and then the solvent was removed. The residue was heated at 155° C. for 17 hr and then allowed to cool to RT. The cooled residue was triturated with MeOH. The solid precipitate was collected by filtration and washed with cold MeOH to give 4.43 g 1A (63% yield). 1H NMR (DMSO-d6): 6.34 (br. s, 1H), 6.75 (br. s, 1H), 7.12 (br.s, 1H); MS: 152 (M+H)+; and RP HPLC ret. t.: 0.36 min (YMC Xterra S 7: 3.0×50 mm column, 2 min gradient, 5 mL/min.

Workup

  1. temperatureThe mixture was heated
  2. temperatureat reflux for 1 hr
  3. customthe solvent was removed
  4. temperatureto cool to RT
  5. customThe cooled residue was triturated with MeOH
  6. filtrationThe solid precipitate was collected by filtration
  7. washwashed with cold MeOH

Sources & evidence

ORD record
ord-da9a758dd8ea4d6ab6ebb1e60045caba
Source dataset
uspto-grants-2008_10
Patent number
US07442700B2

Reaction notes

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